Program Controlled Washing Machine

ABSTRACT

A process section which is adapted in such a way as to meet the requirements of a batch of washing, comprising textiles that are in danger of shrinking, moved during treatment in said process section in a washing drum that is rotatably arranged about a non-vertical axis while water and optionally detergent flows therethrough, wherein the amount of movement thereof corresponds to less than 5% of the possible drive time. As a result, it possible to treat shrink-endangered batches of washing despite mechanical loading by virtue of the small amount of movement of the washing drum, such that the washing can be evenly moistened with the optimum amount of water or lye, thereby optimizing the washing process for shrink-endangered batches of washing, wherein movement occurs exclusively in one direction of rotation of said drum.

The present invention relates to a program-controlled washing machine with a process section, which is tailored to the requirements of a batch of washing comprising shrink-prone textiles, which is moved during treatment in said process section in a washing drum supported in a rotatable manner about a non-vertical axis while water and optionally detergent flow through, with a movement ratio of less than 5% of the possible drive period.

Wash programs known to date for shrink-prone textiles—known as wool or handwash programs—treat the batch of washing in such a manner that the washing drum moving said washing is operated with a reversing rhythm with a movement ratio of less than 5% of the possible drive period in alternating rotation directions, known as “rocking”. The movement input is characterized in that the mechanical conditions of the washing drum and its agitators mean that the batch of washing is not fully turned even after a number of reversing cycles. It is therefore also not certain that it is fully wet and sufficient fluid has passed through for the purposes of cleaning.

The constant change in the rotation direction of the washing drum is intended to prevent the batch of washing becoming knotted during its treatment. However every rearrangement of the washing achieved in one rotation direction is reversed again when the rotation direction changes. This means that items from the top of the batch of washing never come into intense enough contact with moisture and therefore only have a very limited involvement in the washing process. They even remain perceptibly dry at least to some degree after the washing process.

The object of the present invention is therefore to treat batches of washing with a tendency to shrink in such a manner despite little mechanical input due to the lack of movement of the washing drum, that the washing is wet evenly with the optimum quantity of water or washing liquid and therefore the washing process is optimized for shrink-prone batches of washing.

According to the invention a washing machine of the type referred to in the introduction is configured so that movement only takes place in one direction of drum rotation.

It has proven that with such a small movement ratio batches of washing essentially do not tend to become knotted in non-reversing washing drums. In fact batches of washing comprising shrink-prone textiles are regularly smaller batches of washing which do not tend to become knotted. This is prevented in that given the short nature of the overall rinsing process for such a batch of washing, only short and few movement pulses act on the batch of washing. Increased shrinkage of the textiles is not anticipated due to the constantly small movement ratio of the washing drum.

In a refinement of the invention the washing drum has agitators on the inside of its shell, said agitators being equipped with a facility for scooping water from the lower region of the outer tub and for spraying the scooped water down, when they are in a higher position than the washing. This refinement of the invention is particularly advantageous, if the rotation direction of the washing drum corresponds to the direction of action of the scooping facility. This also significantly favors wetting and the flow of fluid through the textiles.

A low rotational speed of approximately 20 rpm has proven very appropriate for this purpose, depending on the geometry of the outer tub/drum system. Its precise value can be optimized further as a function of the geometry and function of the agitators.

In the same way the unidirectional drum movement tailored to the structural features of the outer tub and/or the washing drum has proven particularly suitable with a 10 to 60 second pause. This gives the washing liquid the opportunity to act on the textiles in a sufficiently intensive manner.

The inventive refinement of the washing machine and suitable method steps for this refinement are described in more detail below with reference to an exemplary embodiment of a movement phase of a washing drum. In the drawings

FIG. 1 shows a schematic diagram of a washing drum supported horizontally in an outer tub, with scooping facilities on its agitators,

FIG. 2 shows a known movement section of the washing drum with reference to a diagram and

FIG. 3 shows an inventive movement section of the washing drum with reference to a comparable diagram.

The washing drum 1 shown in FIG. 1 is supported in a horizontally rotatable manner in the outer tub 2. Its washing agitators 3 are equipped with scooping facilities 4 on the side of the shell of the washing drum 1 and have holes 5 on their top sections, through which water scooped up from the lower section of the outer tub 2 is sprayed over the washing 6, when the agitators, like the agitator 3.1 in the diagram, reach a position above the washing 6 due to rotation of the washing drum 1 in the direction of the arrow 7.

If the washing drum 1 is operated in a reversing mode in the known manner according to FIG. 2, at time t₁ it receives a rotation pulse in a positive direction (counter to the arrow direction 7) and at time t₂ it receives a rotation pulse in a negative direction (in the arrow direction 7). This causes the batch of washing 6 in the washing drum 1 to be carried once to the right and to be rearranged and the second time to be carried to the left and returned to its previous arrangement. As it is carried to the right, it remains dry, since the scooping facilities 4 do not scoop water counter to the rotation direction 7 and therefore no water is sprayed from above over the washing 6. In contrast the batch of washing 6 is wet, when it is carried to the left in the arrow direction 7 during rotation, because then the scooping facilities 4 scoop water out of the lower region of the outer tub 2 and spray it down over the washing 6 from an upper position.

According to the invention, in a new and advantageous manner according to FIG. 3 in contrast to the method shown in FIG. 2, the washing 6 in the washing drum 1 is now always moved only in the arrow direction 7, the negative rotation direction, at the same times t₁ and t₂ and in rotation pulses of respectively identical length. As a result water can spray down over the washing 6 with every rotation pulse, so the washing comes into contact with double the quantity of water compared with the prior art. Also the batch of washing 6 is now constantly rearranged, so that the same layer is not always at the top during spraying, which would mean that only this layer would get wet. 

1-6. (canceled)
 7. A program-controlled washing machine comprising: an outer tub; a washing drum supported within the outer tub for rotation about a non-vertical axis; a process section tailored to the requirements of washing shrink-prone textiles that are received within the washing drum while water and detergent flow into the outer tub, the process section including multiple rotational drive sections in which the washing drum is rotated with a movement ratio of less than 5% of the possible drive period, wherein the rotational movement of the washing drum only takes place in one direction in the process section.
 8. The washing machine as claimed in claim 7, wherein the washing drum includes multiple agitators on the inside of the washing drum, each agitator having a scooping facility for scooping water out of the lower region of the outer tub and apertures for discharging the scooped water down onto the washing while the washing drum rotates.
 9. The washing machine as claimed in claim 8, wherein the scooping facilities are formed to only scoop water in one rotation direction of the washing drum that corresponds to the rotation direction during the process section.
 10. The washing machine as claimed in claim 9, wherein the unidirectional drum movement tailored to the structural features of the outer tub and the washing drum can be executed at a rotational speed below the rotational speed at which the textiles lie against the inner wall of the washing drum.
 11. The washing machine as claimed in claim 9, wherein the unidirectional drum movement tailored to the structural features of the outer tub and the washing drum can be executed at a rotational speed in the region of about 15 to 35 rpm.
 12. The washing machine as claimed in claim 7, wherein the rotational drive sections are spaced at an interval of about 10 to 60 seconds from one another.
 13. A method for washing shrink-prone textiles in a program-controlled washing machine comprising an outer tub, a washing drum supported within the outer tub for rotation about a non-vertical axis, the method comprising the acts of: rotating the washing drum with respect to the outer tub in a rotational drive section with a movement ratio of less than 5% of the possible drive period; stopping rotation of the washing drum with respect to the outer tub for an interval between rotational drive sections; and rotating the washing drum with respect to the outer tub in an additional rotational drive section with a movement ratio of less than 5% of the possible drive period, wherein the rotational movement of the washing drum during the rotational drive sections only takes place in one direction.
 14. The method as claimed in claim 13, further comprising providing multiple agitators within the washing drum, each agitator having a scooping facility for scooping water out of the lower region of the outer tub and apertures for discharging the scooped water down onto the washing while the washing drum rotates, the scooping facilities being formed to only scoop water in one rotation direction of the washing drum that corresponds to the rotation direction during the rotational drive sections.
 15. The method as claimed in claim 13, wherein the act of rotating the washing drum is executed at a rotational speed below the rotational speed at which the textiles lie against the inner wall of the washing drum.
 16. The method as claimed in claim 13, wherein the act of rotating the washing drum is executed at a rotational speed in the region of about 15 to 35 rpm.
 17. The method as claimed in claim 13, wherein the acts of stopping rotation of the washing drum with respect to the outer tub for an interval between rotational drive sections has a duration period of about 10 to 60 seconds. 